The Spanish word 'resaca', which means both 'undertow' and 'hangover', has an interesting etymology that combines Gothic and Latin elements. It comes from the Spanish verb 'resacar', meaning 'to draw back', which itself is formed from two parts: the Latin prefix 're-' meaning 'back' or 'again', and the Spanish verb 'sacar' meaning 'to extract'. The verb 'sacar' can be traced back to the Gothic word 'sakan', which meant 'to litigate' or 'to dispute'.

The semantic evolution from 'to draw back' to both 'undertow' and 'hangover' makes intuitive sense. An undertow is literally water drawing back from the shore, while a hangover can be thought of metaphorically as the after-effects that draw you back from wellness to sickness the day after drinking.

The most common related Spanish word is 'sacar', meaning 'to take out' or 'to extract'. This is a very frequent verb that Spanish learners encounter early in their studies. While 'sacar' focuses on the action of taking something out or extracting, 'resaca' took on more specific meanings related to the concept of drawing back, either literally (in the case of water) or figuratively (in the case of hangover symptoms).

While there aren't any direct English cognates from the Gothic 'sakan' root, English speakers might find it interesting that the 're-' prefix in 'resaca' is the same Latin prefix we use in many English words like 'return', 'repeat', and 'rewind' - all of which carry that same notion of 'back' or 'again'.